I usually take my 10 ga. w/ 3 1/2" 4 or 5 shot.
Have handloaded copper plated 4's w/ good sucess.
Let a big tom walk this morning at 66 yards. Thought he was coming in, but he changed directions on me. Probably should have taken him, but that's a long shot. Last time I patterned it, I had 21 pellets in the head and neck at 50 yards. Always tomorrow.

Copper plated shot in and of itself is not a guarantee of a tight pattern. I found some copper shot had a soft lead pellet. Recovered pellets during testing showed they were being squished into partial cubes in a super full turkey choke. The killing pattern was only useful to 40 yards as best, while another load with unplated but harder shot was good to 50 yards.

The point here is... test the loads for yourself.

You need to get, consistently, at least three or four pellets into the brain or neck bones to ensure a kill. Anything less can result in a run off. Anything other than the skull or neck bones is only a flesh wound.

Turkeys are coming back here in Maine but you get some long shots sometimes. I will vote for Hevi Shot #5's also. The boy killed his 1st turkey with them in a 20 ga at 40 yards. That sold me, That's all I use now. Al Baker

Whatever else you do, use high velocity loads. Find the choke that works for your gun, and have at it.

I have found that #4 needs a more open choke - .675 at tightest - at least out my son's 11-87. #5 and #6 shot pattern great at .665, and #6's pattern well down to .655. These are patterns with PORTED CHOKES - which tend to require (my experience/opinion) larger diameters to pattern well. For some reason, at least in my guns, non-ported chokes need to be tighter to produce commensurate patterns - so that's .665 for large shot, and .655 for the smaller.

I shoot an SP-10 for turkeys and use high velocity Federal #5's (2 oz, 1300 fps). Again - my ported Hastings turkey choke at .695 produces outstanding patterns. I also have a .685 non-ported which does OK, but does not maintain the pattern beyond about 40 yards. With the Hasting's tube, I have complete confidence out to 60 yards, and have killed them like they were hit with a baseball bat at that range.

Find your magic combo. It requires some time, and maybe some expense if you can't return a choke tube that just doesn't work - but hopefully the above will help narrow the search.

Wow.you really need a three inch shell to kill a Turkey?I've always used a 2 3/4 shell.if a Turkey walks away from a 1 3/8 ounce of 4 or 5s going 1350fps someone just plain missed the shot.never figuered out why a 3 inch shell is necessary to kill a Turkey at 30 or 40 yards?????.seems like a total overkill.I think the ammunition companies promote that more than anything.sorry just getting that out there.good luck Turkey hunting.